The instant invention is concerned with the field of herbaceous plant materials from which there may be realized in one form or another medicinal compounds such as drugs and other pharmaceuticals.
At the present time, the herbaceous plant material cannabis is grown, processed, and utilized in the United States under Government regulations and controlled by Government agencies. Research and study is carried out under the control of Federal Agencies, and work is being carried out in the medical field by medical laboratories and others relative to the use of the drug as a therapeutic pharmaceutical, and relative to its use also as a social euphoriant.
It is understood that difficulties are often encountered by those engaged in government research and medical studies dealing with cannabis. The government has for some time provided researchers with plant material both in loose form and in pre-rolled cigarettes. Despite careful controls on the varieties grown under government supervision to provide this experimental material, the amount of delta-9 tetrahydrocannabinol can still vary widely from sample to sample. The only current methods in use that provide a means to decarboxylate the cannabinolic acid in the plant to the active delta-9 tetrahydrocannabinol are destructive both to the plant material, and to whatever delta-9 tetrahydrocannabinol is actually created.
Cannabis is known to contain the chemicals delta-9 tetrahydrocannabinol and cannabidiol, 95% of which in nature are present in the precursor acid states. This suggests that these acids are the original products of biosynthesis, and that the non-acid forms are decarboxylation products according to the following reactions: ##STR1##
Both delta-9 tetrahydrocannabinol and cannabidiol exhibit no pyschoactive properties in their acid forms. Before any psychoactive activities are affected, delta-9 tetrahydrocannabinol and cannabidiol must be decarboxylated. This is generally accomplished by the administration of heat to the point at which the carboxylic acid radical is removed from the molecule.
It is theorized that delta-9 tetrahydrocannabinol serves the plant as a chemical deterrent both to birds, and to insects. Those birds which would eat the oil-rich hempseed are repelled by minute amounts of delta-9 tetrahydrocannabinol, which is especially present in the flowering tops of the plant. Later, when the seed is mature and hard, the coverings or bracts part, exposing the seed. It can then be eaten by the birds, which void a percentage of the hard seeds which make the passage through the bird's digestive tract intact. In this way the plant is propagated, since insect pollination is rendered impossible by the repellent nature of the delta-9 tetrahydrocannabinol. As in the case of many active and effervescent substances, delta-9 tetrahydrocannabinol is easily oxidized upon exposure to the oxygen in the atmosphere, yielding cannabinol, a chemical with no apparent psychoactive or repellant properties. (J. Levine, J. American Chem. Soc. 66, 1868 (1944). The oxidation reaction is as follows: ##STR2## It is suggested that the production of the acid precursor by the plant is to allow a slow and steady production of delta-9 tetrahydrocannabinol by means of the heat of the sun during the growing season of the plant. In this way, as delta-9 tetrahydrocannabinol oxidizes to cannabinol, it is constantly being replaced by fresh supplies realized by the decarboxylation of the less active acid form. It has been found that, upon harvest, nearly 95% of the possible delta-9 tetrahydrocannabinol is still in the acidic, non-active form.
An effective method and associated apparatus are therefore needed to accomplish the rapid and efficient conversion of the plant substance to maximize the content of the active ingredient.